I am trying to figure out what typical ratios are for monomer/cross-linker/template solution in MIPs to have a starting point for my experiments. Also, if it appears there needs to be some modifications to the polymer, which of the three factors should be adjusted?
Since you work with crosslinked functional monomers you should have an excess of monomers/crosslinkers as compared to your template. Below you can see a comprehensive study (not from me) where they varied these ratios.
Since you work with crosslinked functional monomers you should have an excess of monomers/crosslinkers as compared to your template. Below you can see a comprehensive study (not from me) where they varied these ratios.
monomer : template most important and should be estimated from the functionality of template (number of functional groups to form non-covalent bonds with monomer) and functionality of monomer and then take monomer in an excess. E.g. template has 4 hydroxyls and monomer one carbonyl group, thus estimated ratio 1:4 but to shift the equilibrium to pre-polymerization complex formation one should prefer 1:5 or even 1:5
I would say that depends on the size of the template and flexibility you need (as a rule of thumb: the larger your template the less crosslinker you need) and on the polymer type.
Unfortunately, with MIPs there is no one recipe that fits all templates. But you can make a good guess beforehand. Have a look in the literature for similar templates and what worked there. The MIP database is a great resource which allows you to search for a certain template:
http://www.mipdatabase.com/
(you can go to keywords and then templates)
Here are also some personal experiences: I worked with proteins and typically used something like 5% template (this was also what my former boss had initially suggested to start with so it seems to be a good number in general, I did vary it at some point but the study still came back to the old 5%). I would say to make a polymer you need a certain quantity of monomer/crosslinker to form a proper polymer (if you use too much template your polymer wont form) so that is more or less fixed.
The monomer/crosslinker ratio depends very much also on the polymer you use and the application. I worked mostly with methacrylates and used about 30% crosslinker (EGDMA) for films and up to 60% for nanoparticles. Something that I also really liked was working with PDMS. There I used a fixed ration and varied the viscosity of the polymer by chosing the prepolymerisation time
This is the paper for the PDMS: http://pubs.rsc.org/is/content/articlehtml/2012/an/c2an15927a
I hope this helps, Romana
You could use 1:3 or 1:4 template:monomer ratio and 1:5 monomer:cross-linker ratio if you really don't know where to start. These are stated in journals. In the end, your monomer: cross-linker ratio will ultimately depend on your template.
- Badges
- Science topic